Heater shuts off when the pump speed is reduced on a variable-speed pump.

Safety: Turn off power to heater and pump before adjusting wiring or switches.

• Increase pump speed: Set the variable-speed pump to a higher RPM when the heater is running to meet the heater’s minimum flow requirement.
• Clean filtration: Backwash or clean the filter and empty baskets to reduce system resistance.
• Check bypass: Ensure any manual bypass around the heater is adjusted correctly so sufficient flow passes through the heater.
• Adjust pressure switch (if allowed): Some Pentair models allow minor adjustment of the water pressure switch. Follow the manual carefully; do not set it so low that it fails to protect against no-flow conditions.